A few months ago i received a similar survey from Tektronix. No comparison with other brands but also choosing from imaginary scopes. I think it was even more than 10 of those comparisons in the survey.
I guess this was a survey to find out which parameter is important and how much more would the customer pay for it. For example is the customer willing to pay more for 12bit, higher sample rate, more memory and so on. Or what would the customer choose if you could either have 12bit or more memory for the same price. So trying to find out which parameter is important and which is not.
For your Rigol survey it seems they also want to know how much the brand name is worth i guess?